1. Field
The described technology relates generally to an organic light emitting diode display, and more particularly, to an organic light emitting diode display emitting light in dual-sided directions.
2. Description of the Related Technology
Organic light emitting diode displays have self-emissive characteristics, and differ from liquid crystal displays (LCD) by not requiring a separate light source and being relatively thin and lightweight. Organic light emitting diode displays exhibit high quality characteristics such as low power consumption, high luminance, and short response time.
Organic light emitting diode displays generally include a first substrate with organic light emitting diodes, and a second substrate, facing the first substrate, to protect the organic light emitting diodes of the first substrate.
Conventional organic light emitting diode displays may be classified as one-side emission type displays which allow images to be viewed in one direction, and dual-side emission type displays which allow images to be viewed in two directions.
One-side emission type displays generally include a reflective electrode, a semitransparent electrode, and an organic emissive layer disposed between the reflective electrode and the semitransparent electrode, to emit light. The organic emissive layer emits light in one direction, in the direction of the semitransparent electrode, such that images are viewed on that side.
Dual-side emission type displays generally include two semitransparent electrodes placed facing each other, and an organic emissive layer disposed between the semitransparent electrodes, to emit light. The organic emissive layer emits light in two directions, in the direction of both semitransparent electrodes, such that images are viewed on both sides.
In one-sided emission displays, the light emitted from the organic emissive layer is repeatedly reflected between the reflective electrode and the semitransparent electrode such that there is a considerable micro-cavity effect as well as high light emission efficiency. In dual-sided emission displays, the light emitted from the organic emissive layer is reflected between the semitransparent electrodes less repeatedly than with the one-sided emission displays; the micro-cavity effect is thus reduced, and the light emission efficiency is also reduced.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.